ADE7569ASTZF16 Analog Devices Inc, ADE7569ASTZF16 Datasheet - Page 125

• Manufacturer Part Number: ADE7569ASTZF16
• Description: IC ENERGY METER MCU 16K 64LQFP
• Manufacturer: Analog Devices Inc

Specifications of ADE7569ASTZF16

• Applications: Energy Measurement
• Core Processor: 8052
• Program Memory Type: FLASH (16 kB)
• Controller Series: ADE75xx
• Ram Size: 512 x 8
• Interface: I²C, SPI, UART
• Number Of I /o: 20
• Voltage - Supply: 3.135 V ~ 3.465 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Ic Function: Single Phase Energy Measurement IC
• Supply Voltage Range: 3.13V To 3.46V, 2.4V To 3.7V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Take care when changing the interval timer time base. The
recommended procedure is as follows:
1.
2.
3.
4.
The RTC alarm event wakes the 8052 MCU core if the MCU is
in PSM2 mode when the alarm event occurs.
RTC CALIBRATION
The RTC provides registers to compensate for the tolerance of
the crystal frequency and its variation over temperature.
Up to ±248 ppm frequency error can be calibrated with the RTC
circuitry. The compensation is fully digital and implemented by
adding or subtracting pulses from the crystal clock signal.
The resolution of the RTC nominal compensation SFR
(RTCCOMP, Address 0xF6) is ±2 ppm/LSB or 0.17 sec/day/LSB.
The RTC compensation circuitry adds the RTC temperature
compensation SFR (TEMPCAL, Address 0xF7) and the RTC
nominal compensation SFR (RTCCOMP, Address 0xF6) to
determine how much compensation is required. The sum of
these two registers is limited to ±248 ppm or 42.85 sec/day.
Calibrating the RTC
The nominal crystal frequency can be calibrated by adjusting
the RTCCOMP SFR so that the clock going into the RTC is
precisely 32.768 kHz at 25°C.
Calibration Flow
An RTC calibration pulse output is provided on the P0.2/CF1/
RTCCAL pin. Enable the RTC output by setting the RTCCAL
bit in the interrupt pins configuration SFR (INTPR,
Address 0xFF).
The RTC calibration is accurate to within ±2 ppm over a 30.5 sec
window in all operational modes: PSM0, PSM1, and PSM2. Two
output frequencies are offered for the normal RTC mode: 1 Hz
with FSEL = 00 and 512 Hz with FSEL = 01 in the interrupt pins
configuration SFR (INTPR, Address 0xFF).
If the alarm interval SFR (INTVAL, Address 0xA6) is going
to be modified, write to this register first. Then, wait for
one 128 Hz clock cycle to synchronize with the RTC,
64,000 cycles at a 4.096 MHz instruction cycle clock.
Disable the interval timer by clearing the ITEN bit in the
RTC configuration SFR (TIMECON, Address 0xA1).
Then, wait for one 128 Hz clock cycle to synchronize with
the RTC, 64,000 cycles at a 4.096 MHz instruction cycle
clock.
Read the TIMECON SFR to ensure that the ITEN bit is
clear. If it is not, wait for another 128 Hz clock cycle.
Set the time-base bits (ITS) in the TIMECON SFR to
configure the interval. Wait for a 128 Hz clock cycle for this
change to take effect.
ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
Rev. B | Page 125 of 152
A shorter window of 0.244 sec is offered for fast calibration
during PSM0 or PSM1 mode. Two output frequencies are
offered for this RTC calibration output mode: 500 Hz with
FSEL = 10 and 16 kHz with FSEL = 11 in the INTPR SFR.
Note that for the 0.244 second calibration window, the RTC is
clocked 125 times faster than in normal mode, resulting in
timekeeping registers that represent seconds/125, minutes/125,
and hours/125 instead of seconds, minutes, and hours.
Therefore, this mode should be used for calibration only.
Table 138. RTC Calibration Options
Option
Normal Mode 0
Normal Mode 1
Calibration Mode 0
Calibration Mode 1
When no RTC compensation is applied, RTCCOMP and
TEMPCAL are equal to zero, the nominal compensation
required to account for the error in the external crystal can be
determined. In this case, it is not necessary to wait for an entire
calibration window to determine the error in the pulse output.
Calculating at the error in frequency between two consecutive
pulses on the P0.2/CF1/RTCCAL pin is sufficient.
The value to write to the RTCCOMP SFR is calculated from the
% error or seconds per day error on the frequency output. Each
LSB of the RTCCOMP SFR represents 2 ppm of correction
where 1 sec/day error is equal to 11.57 ppm.
During calibration, user software writes the current time. Refer
to the Read and Write Operations section for more information
on how to read and write to the RTC timekeeping registers.
RTCCOMP
RTCCOMP
=
=
5000
2
×
FSEL
00
01
10
11
11
1
×
.
57
(%
×
Error
(
sec/day
)
Calibration
Window (sec)
30.5
30.5
0.244
0.244
Error
)
f
(Hz)
1
512
500
16,000
RTCCAL